Are your medical bills piling up? You’re not alone. About 79 million Americans struggle with medical debt, according to a recent Commonwealth Fund report. In 2007, nearly two-thirds of bankruptcy filings were linked to medical problems, and a whopping 78 percent of those filers had insurance, Harvard researchers found.

There are ways to cut your costs though and avoid that fate. Here’s how:

1. Know what’s covered
Willful ignorance is the biggest trap consumers fall into, says Lisa Norris, co-president of the nonprofit Alliance of Claims Assistance Professionals. To avoid sticker shock, find out beforehand what an out-of-network doc charges, and what percentage of her fee your insurer will cover. Insurers assign “allowed amounts” for a service; if your out-of-network doc charges more than that, you’re responsible for the difference —plus the co-pay.

Be sure to know the cap on your coverage, too. Choosing a policy with an “unlimited cap” instead of a “lifetime cap” can prevent you from maxing out too soon, says Larry Gelb, founder and CEO of CareCounsel, a health-advocacy company in San Rafael, California. And take advantage of your plan’s preventive services, such as gym membership and smoking-cessation programs, says Michelle Katz, author of Healthcare for Less. You could save where you didn’t anticipate.

2. Scrutinize your bills
Just like hotels, phone and cable companies, medical billers count on you not looking at your statement before you pay. Requesting an itemized bill and reading it with a magnifying glass could save you 20 to 40 percent on billing errors, Katz says. She typically finds at least three mistakes on hospital bills, from incorrect dates of service (leading, say, to charges for extra nights in a hospital room) to fees for medicines and physical therapy that patients never received. If you stay in the hospital, be sure to ask for your medical records before you go so you can compare them to your bill when it arrives.

3. Challenge those fees
Take advantage of your right to appeal a claim. Know how long you have to mount a challenge, and if that window opens the day you’re treated or the day you receive your bill. Document everyone you talk to, the date and time of your calls, and what you’re told. Ask for a supervisor, and be nice: After many conversations with an emergency room’s billing director, Katz says she got the entire $11,000 bill for her now-ex-husband’s cardiac arrest written off. “In the end I sent her flowers and a big thank you,” she says. “To write off the bill was worth a dozen roses.”

4. Access your records
You know it’s a good idea to get a yearly credit report. Do the same for your health. Just as a bank will review your credit when you apply for a mortgage, health insurers will ask the Medical Information Bureau for your medical records if you’ve applied for an individual policy. If they show you have a pre-existing condition or have taken certain medical tests, you might be rejected. You’re entitled to a free copy of the report annually and can dispute the information if it’s wrong.

5. Comparison shop
When you can, opt for generic or over-the-counter meds instead of brand names. That could save you tens to hundreds of dollars, Norris says. And check out the big-box stores. “There will be huge variations between Costco or Wal-Mart and your local mom-and-pops—twice as much if not more,” says Gelb. Hospitals mark up the pills they give you, so get your doctor’s permission to bring meds inside, Katz says. And if you’re planning for certain procedures, such as hip replacement, compare prices on your insurer’s Web site or call around first, Gelb adds.

The bottom line: Educate yourself and shop around. When it comes to healthcare, a little bit of time and effort could save you a lot of money.